Articles with non-wetting or water-repellent surfaces are used in a wide variety of applications. A relatively recent approach in creating a non-wetting surfaces is to treat the surface so that it is rough or textured and then coat the surface with a material having low surface energy, such as a polymer or a fluoroalkylsilane. These surfaces, while generally nonwetting, face material-related drawbacks that limit their use in industrial applications, and other applications in which the surface is exposed to harsh environments.
For example, surfaces treated with polymers or fluoroalkylsilanes have insufficient mechanical resistance, chemical resistance, and thermal stability for many applications. While metals and ceramics are often useful for surfaces exposed to harsh environments, they are generally hydrophilic and do not provide desired non-wetting, water-repellent properties.
Another drawback of existing non-wetting surfaces is that they are susceptible to impalement, which reduces or destroys the non-wetting capabilities of the surface. Impalement occurs when an impinging liquid (e.g., a liquid droplet or liquid stream) displaces the air entrained within the surface textures.
There is a need for articles with improved non-wetting surfaces that can endure harsh industrial environments and that resist impalement.